“…The energy band gap (E g ) was calculated by the Kubelka− Munk equation (eq 1) using the DRS results, where α is the adsorption coefficient, h is the Planck's constant, ν is the incident light frequency, A is the proportionality coefficient, and E g is the band gap energy (eV). 54 The E g of Ag 3 PO 4 was 2.73 eV, while most of MIL x , excluding MIL 0.25 (3.1 eV), exhibited an E g of approximately 2.4 eV, independent of the Co/Fe ratio. Consistent E g implies the negligible impact of Co/Fe ratios on the light absorption capacity for MIL x , probably because the light absorption of MIL x occurs primarily through ligand to metal charge transfer (LMCT).…”